The objective of this project is to encapsulate purified antigens of B. pertussis into biodegradable, biocompatable microspheres in an immunogenic form for use as an experimental oral pertussis vaccine in an animal model of B. pertussis infection. Preliminary studies have shown that B. pertussis filamentous hemagglutinin (FHA) can be successfully encapsulated in biocompatible, biodegradable microspheres. FHA is one of several pertussis antigens that may allow B. pertussis bacteria to adhere and cause infection in the respiratory tract. FHA microspheres elicited a profound serum antibody response in mice that remained a thigh levels for at least 70 days after immunization. This work has established that the preparation of antigen for encapsulation and the encapsulation process itself does not destroy the antigenic integrity of FHA, a prerequisite to the evaluation of these microspheres for potential use as an oral pertussis vaccine. Experiments to determine the mucosal immunogenicity of these microcapsules are currently in progress. The significance of this project lies in its application to the development of an oral vaccine for pertussis.